To meet the demand for wireless data traffic having increased since deployment of 4G (4th-Generation) communication systems, efforts have been made to develop an improved 5G (5th-Generation) or pre-5G communication system. Therefore, the 5G or pre-5G communication system is also called a ‘Beyond 4G Network’ or a ‘Post LTE System’.
The 5G communication system is considered to be implemented in higher frequency (mmWave) bands, e.g., 60 GHz bands, so as to accomplish higher data rates. To decrease propagation loss of the radio waves and increase the transmission distance, the beamforming, massive multiple-input multiple-output (MIMO), Full Dimensional MIMO (FD-MIMO), array antenna, an analog beam forming, large scale antenna techniques are discussed in 5G communication systems.
In addition, in 5G communication systems, development for system network improvement is under way based on advanced small cells, cloud Radio Access Networks (RANs), ultra-dense networks, device-to-device (D2D) communication, wireless backhaul, moving network, cooperative communication, Coordinated Multi-Points (CoMP), reception-end interference cancellation and the like.
In the 5G system, Hybrid FSK and QAM Modulation (FQAM) and sliding window superposition coding (SWSC) as an advanced coding modulation (ACM), and filter bank multi carrier(FBMC), non-orthogonal multiple access(NOMA), and sparse code multiple access (SCMA) as an advanced access technology have been developed.
In order to meet traffic demands of wireless data which has continuously increased, the wireless communication system has been developed in a direction for supporting a higher data transmission rate. A currently developed wireless communication system seeks to develop a technology that mainly improves a spectral efficiency to increase a data transmission rate. However, it is difficult to meet the traffic demands of wireless data that have increased heavily through improvement of the spectral efficiency alone.
One of the other methods to increase the traffic demands of wireless data is to use a frequency band of a very wide bandwidth. A frequency band used in a conventional mobile communication cellular system generally corresponds to 10 GHz or lower, thereby having difficulty in securing the wide frequency band. Accordingly, it is required to secure a broadband frequency in a higher frequency band to increase data capacity. However, as the frequency for wireless communication increases, a propagation path loss increases and, accordingly, a propagation arrival distance becomes relatively short and a service area (coverage) becomes reduced. Beamforming technology is one of the important technologies for mitigating the propagation path loss and solving the reduction in the propagation arrival distance.
Beamforming may be divided into transmission beamforming performed by a transmitting end, and reception beamforming performed by a receiving end. In general, transmission beamforming increases directivity by concentrating a propagation arrival area in a particular direction by using a plurality of antennas. A form in which the plurality of antennas are arranged may be referred to as an antenna array, and each antenna included in the array may be referred to as an array element. The antenna array may be configured in various types such as a linear array and a planar array. When transmission beamforming is used, a transmission distance increases through an increase in signal directivity. Further, since the signal is hardly transmitted in another direction other than the directed direction, signal interference for another receiving end significantly decreases. The receiving end may perform beamforming for a received signal by using a reception antenna array. Reception beamforming concentrates reception of radio waves in a particular direction to increase received signal sensitivity incident from the corresponding direction and excludes signals incident from directions other than the corresponding direction from the received signal to provide a gain in blocking an interference signal.
As described above, in order to secure a wide frequency band, an ultra-high frequency, that is, a millimeter (mm) wave system is expected to be introduced, in which case a beamforming technology for overcoming the propagation path loss is being considered.
The above information is presented as background information only to assist with an understanding of the present disclosure. No determination has been made, and no assertion is made, as to whether any of the above might be applicable as prior art with regard to the present disclosure.